Float collar and cementing shoe



' Jan. 22, 1946. R. N. BURNETT FLOAT COLLI-XR AND CMENTING SHOE Filed y.July i12, 1941- N .mi

TQQ/viv Patented Jan. 22, 1946 (enlise-19,- o A, Y s tubing amusing-,w "nisseamffbx.thelfloatelg field.Y practice. Thef g-enenal purpose of suehmpreff Y cedureisthe exclusionA of water: from produptiuel formations.v Oil` Well -Gernentingv requires the placing ofvcement slurry at; tideprenderv plaeein the: wel1 `toffcerrrlent astri-ng of easing; and to sea-l,

01T. the.k passage vofv iud or gas past the peint which it is desired to plug. Y

In running. easing, for thisfvpurpeset, espeeially in; Wells which attain great` depths a tremendous strain; isfrplaeed upenfeduipment` due tagtheenen4 mous weightof the easing.

Y It.A is .one -of the -olttiectsrI -of -this invention. -to' provide a. means for sealing 01T the end ot the Casina se t0 Permit theasng te be ',buoted up hythefluid which isfinthewell.

This isaecompllishe@ by closure-Which will, remain closed during,V .the sun.-

ning of 'theI casi-ng: Se, aste exclude thel.fpxltlnaiionA Huid from the interior 'of the; casi-ng 01: .tubing whichy isrbeing, rune and so Vperttnitsthe bueyant actionA of the fluid. to; relievei the. strain o n the lowering and suspending equipment. ,y K u InL order that this: fleat. collar Ymay alsdbeusable ,asa eementing` shoer provisionV ismade .in the .oat collar of this 'inventionlforlthe opening of..v the fvallve on theVim-positien ofhyd:saillie.presfl sure. to permit the'd'seharge ef the cement there,-

through. "Bymeans of vthis hydraulically oper-L.A

ated value. structure` af quick vclosing013eiajtikzinllsQ made. possible Whiehseals. the V.closure upon .thef

release of"hydra'ulic pressure, thusn Ap1:talenti-rig the backward -migration of :cement intav tubing on casing;

It 'is an; object 0f' um inventinn, to. dense "aA bat. collar andl easing. shoe which may be. Vem-l ployed 'in any of the 'method's. of cemelting,..

In employing the floatcollar inany Vi'l'ies'e,

methods, a number of advantages, areattainedf The flat collarx may'beplaced either alt'the endl of the. tubing when the't'ubing. method used; or aty the endl 0f the casing 4when the casing', method's used'. It will' permittheffloating'g 'in'of the casing.. or tubing. to relieve the strain on .the

troduced it isA kept away from contamination by.

amount 'of cementhas Abeen"in't'oduce'd 'into 'the holeffer eementing,

This... oat collar and -eementing issalso usefut the :ao-called full-l holeemethed of. ee.` mentingf combination. strings-oi easing A, com# bination string of casing is composed ',oi` blank4 casing-stmt fimperferate; casi-ng; .and pentora-te vscreen vliner. cement-ing this. typegfe cnmbinationr strings; difficulty' has beemfeundl inwaslngg-overthe whole length of: easing/due ta met that the:V Ygerrierate-,linen idees: nntpenfthezgstreamitogpass theV fullf length foi the liner;vv Te avoid'. this diiculm. it is desirable gte@ emplny .aV ,Linen :of .fsuehz Yeorxstnuetum that, it is.: inmertnnateazduningt the.: Washing:y operations; andi mambeaeither driliect outorma-de perferate-whem thee cementing; operation. has been completed; Such; az linenmayfbe theefenm` ntliner "diselosedi-in'. the copending applieatfinnu .Serial. No; 30;?.l1? The wailsvdf thexlner venrrtain solubleportinns: upon, meest-ism with vare eateneouttn ,pnt vide the desimedipassagesm the wallsz'thereof.

1 Inl .cement-ing-us'uchi a eemhnatim strng:the: flea/t collar and cerner-117mg vshoelofthis:ixmeantime may vbe Apaeedeither YatY the fendi "of ther string" or at apoint: between the; impertorate' casingxfandi the perform casing. Thenemen-tingK procedurel then :nuclithe'sameasittftheme'theds her-'ein descnibed ",'Ihe-y cement disehazrges through the opexrportsof nemen-ting shoe Aunder the' v uerrce-of hydraulic pressure amdiisplaee'd po ing ring I2.

preventing the intrusion of cement from the ex-k In the barrel I is provided a recess 2, into which is fitted a helical spring 3. Inside the barrel I is positioned a slidable sleeve 4 provided with a lip B which is resiliently supported upon said spring 3. The lower end'f said sleeve 4 is provided with a series of cut out portions 1, whose function will be described later. On top of said lip 6 of the sleeve 4 is set a second sleeve`8 provided with ports I0, equal in number to the ports 5. The end of the sleeve 8 is closed by a disc I I', which is screwed in or otherwise attached to the sleeve. The sleeve 8 is retained in place by a re-v taining ring I2, which the barrel I.

The barrel assembly is screwed onto the end of the tubing or casing I4. In the event additional lengths of casing or tubing or screen are to be attached to the end of the barrel I, it may be done as shown at I3.

On the lowering of the casing or tubing into the well, the hydrostatic pressure of the fluid outside the casing is transmitted through ports 9 against the bottom of the disc I I L A hydrostatic pressure is created in the chamber between said discs and the sleeve 4 and sleeve 8 are moved upward against the retaining ring I2 so that the ports I are moved out of register with ports 5 and the interior of the tubing or casing is sealed as shown in Fig. 2.

When the cement has been introduced and deposited inside the tubing or casing above the upper disc II', hydraulic pressure, generated for example by means of the pump I5, will move the sleeve 8 and the sleeve 4 downward against the spring 3 and overcome the hydrostatic pressure of the iluid, causing its discharge from the interior of the chamber between the discs II and II' through the ports 9. Upon the downward motion of the sleeve 8, port I0 comes into register with the port 5, thus permitting the discharge of the cement through port I0 and port 5 into the exterior of the casing or tubing.

The cut out portion 'I of the sleeve 4 is pro; vided for the purpose of keeping the ports 9 open. When this cement has been discharged through I0 and 5, the pump pressure is relieved and the hydrostatic pressure on the exterior of the casing, acting through open ports 9 and the spring will move the sleeve 4 and therefore the sleeve 8 upf ward until the sleeve 8 abuts against the retain- This seals the ports again, thus is screwed into position in terior of the casing back into the interior of the casing. When the cementing operation is vcompleted, the discs II and II', which may be conveniently of cast iron, may be drilled through by means of a sh tail bit or any other cutter, as Will be well understood by those skilled in the art.

As will be observed from the construction and operation of this combined iloat collar and casing shoe, the tubing or casing may .be floated in because during the descent of the tubing or casing which is attached to the float shoe, the interior of the tubing or casing is sealed off from the ex- 3"'siiice it iimits the mixing of the cement with terior by means of the discs I I and I I which form a closure upon the bore of the tubing I4. .The interior of the casing or tubing above the disc II may be empty or may contain a desired amount of iluid and thus a controlled bouyancy of the string of tubing or casing is attained. This buoyancy will relieve the strain on the lowering equipment.

The casing shoe is operable with the open hole cementing method, since' the valve structure is operated by hydraulic pressure and does not need thecooperation of an inserted plug for its lunctioning. However, it can be used with the plug method of cementing, the plug being so designed as to seal the ports I The use of a combination float collar and cementing shoe also insures that the interior of the casing or tubing into which the cement is to be placed is not contaminated by the fluid which is inthe well. As is well known, if mixed with cement, such fluid weakens the strength of the cement. The employment of a hydraulically operated cementingl shoe permits of a rapid closure of the cement ports which insures that lcement will not back up into the casing when the pressure is relieved at the pump.

The provision of side wall ports as formed in this invention permits of large openings through which the cement will pass without excessive agitation at the points of introduction into the annulus behind the casing. This is an advantage the fluid in this annulus and thus insures a cement of high strength.

The use of closure discs permits of an easy reopening of the passage by means of a simple cutter without introducing a constriction in the tubing or casing if the tubing or casing a result of the cementing operation,vto remain in the bore hole.

It is to be understood that the foregoing description of an embodiment of the invention is illustrative only and various changes and modifications may be made therein without departing from the spirit of the appended claims.

What is claimed is:

1. A combination float collar and cementing shoe which comprises a barrel, ports in said barrel, means for attachingY said barrel to tubing or casing, a sleeve in said barrel, ports in said sleeve, resilient means to hold said sleeve so that the ports in said sleeve are out of register with the ports in said barreland said sleeve ports are sealed against the wall of said barrel, and a permanent closure for the lower end of said sleeve to prevent flow of fluid through said bore from passing through said sleeve and passing said closure.

2. A combination float collar and cementing shoe which comprises a barrel, upper ports in said barrel, means for attaching said `barrel to tubing or casing, a retaining ring in the upper portion of said barrel and secured to said barrel, a sleeve slidably mounted in said barrel below said retaining ring, ports in said sleeve, ya closure posiltioned in said sleeve below the ports in said sleeve, said closure entirely closing oil the lower end of said sleeve, a second sleeve slidably mounted in said barrel abutting said rstmentioned sleeve below said closure, a resilient support for said second sleeve normally holding said rst and second mentioned sleeves at their upward extremity of motion in said barrel against said retaining ring so that said first mentioned ports in said barrel and the ports in said first mentioned sleeve are out of register, ycontinuallyopen ports in the barrel beneathv said closure, and a second closure in said barrel beneath said second mentioned ports and entirely closing the bore of said barrel, wherebyk upon the imposition in the interior of said barrel above the closure in the rst mentioned sleeve of hydraulic pressure in excess of the combined pressure exerted upwardly against the closure by said resilient support and the hydrostatic pressure in the barrel, said first mentioned sleeve moves downwardly to bring the ports therein into register with the rst mentioned ports inthe barrel, said resilient support being arranged, upon relief of said hydraulic pressure, to move the rst and second mentioned sleeves upwardly until the first mentioned sleeve engages the retaining ring, thereby moving the ports in the first mentioned sleeve out of register with the first mentioned ports in the barrel.

3. A valve structure for oil well tubing comprising a barrel, a port in said barrel connectingl the inside and outside of said tubing, a sleeve in said barrel slidably mounted in said barrel, a port in said sleeve, a diaphragm in said sleeve below said last-named port, and a second port in said fbarrel beneath said diaphragm connecting the of said member against flow of uid through said tubing, means for attaching said member to said tubing orcasing,'a side wall port in said tubular member connecting the interior of said tubing with the exterior thereof above said closure, an hydraulically operated sleeve in said tubular member, a yieldable support for said sleeve, a

` port in said sleeve, hydraulically actuated means interior of'said barrel beneath said diaphragm with the exterior thereof during the slidingmotion of said sleeve, whereby on imposition of hydraulic pressure in the interior of said barrel above said diaphragm said sleeve slides to `bring associated with said sleeve for moving it against the yieldable support upon the imposition of hydraulic pressure within said casing, a stop for said sleeve to limit its motion upon the imposition of the hydraulic pressure, said port in said sleeve being in register with the port in said tubular member when said sleeve has reached said stop, said sleeve moving in the opposite direction upon the relief of said hydraulic pressure, whereby said ports move out of register upon said latter motion of said sleeve, and a stop for said latter motion.

5. An oil well cement device adapted to be attached to a string of tubing or casing to be used in a cementing operation in a bore hole, which comprises a tubular member, means for attaching said member to said tubing or casing, a port connecting the interior of said tubing with the exterior thereof, an hydraulically operated valve structure in said member, a closure for the the two rst-named ports into register and on bore of said member positioned in said valve structure for maintaining the bore of said tubular member closed, said valve structure being operable to Vopen said port upon the imposition of hydraulic pressure in the interior of said member, while maintaining the bore of said member closed, and to close said port upon the release of said hydraulic pressure while maintaining the bore of said member closed. Y

- SYLVESTER HOFFMANN. Eecutor of the Estate of Robert N. Burnett,

Deceased. 

